Research Of The In-situ Transesterification Preparation Of Biodiesel From Oilseed

The development of diversified energy system has become an important strategy in the world with the reduction of fossil energy reserves. Biodiesel attracted widespread attention due to its excellent reproducibility and environmental protection, the conventional transesterification is the main method for biodiesel industrial production. The in situ transesterification preparation of biodiesel without extracting oil from the raw materials compared with the conventional transesterification, it used raw materials mix with methanol to preparating biodiesel. Methanol plays two significant roles in the process of reaction, on the one hand it is the extractant to excerpt lipid from raw materials, and one the other hand is also react reactant to process transesterification with the excerpted lipid. Therefor, the in situ transesterification is an efficient method for preparation of biodiesel.The Jatropha curcas, the rubber seed and the benevolence of paint seed have been used in this experiment to preparating biodiesel by in situ transesterification under the catalysis of H2SO4. The results of optimal experimental condition for preparation of biodiesel using Jatropha curcas as raw materials are as follows: the ratio raw materials to methanol(m/m) is 1:12, the concentration of the catalyst is 0.2mol/L, the temperature is 65±2℃, the reaction time is 15 h, the yield of biodiesel is 29.40% under these conditions. The results of optimal experimental condition for preparation of biodiesel using rubber seed as raw materials are as follows: the ratio raw materials to methanol(m/m) is 1:12, the concentration of the catalyst is 0.2mol/L, the temperature is 65±2℃, the reaction time is 15 h, the yield of biodiesel is 17.50% under these conditions. The results of optimal experimental condition for preparation of biodiesel using the benevolence of paint seed as raw materials are as follows: the ratio raw materials to methanol(m/m) is 1:12, the concentration of the catalyst is 0.1mol/L, the temperature is 65±2℃, the reaction time is 15 h, the yield of biodiesel is 8.50% under these conditions.Taking the Jatropha curcas as an example, using Box-Behnken center combination experiment of response surface analysis method, the ratio raw materials to methanol(m/m), the concentration of the catalyst and the reaction time three factors and there interaction effect on the yield of biodiesel was examined, the temperature fixed at 65±2℃. The results of optimal experimental are as follows: the ratio raw materials to methanol(m/m) is 1:13.77, the concentration of the catalyst is 0.22mol/L, the reaction time is 18 h, the yield of biodiesel predicted is 31.16% under these conditions, the verification experiment has been carried on and the result is 30.57%. It proved the model is reliable, it can offer help for the practical production.The in situ transesterification preparation of biodiesel without extracting oil from the raw materials, the process costs have been reduced and the crafts have been shorten, it achieve the conversion of biodiesel from the oily materials. The method is practical and reliable by experiment verified.